The present invention is related to a pneumatic tool, and more particularly to an airway airtight structure of pneumatic tool.
FIG. 1 shows the high pressure airflow path of a conventional pneumatic tool 1. A connecting airway 4 is formed between the pneumatic cylinder 2 and the main body 3. The connecting airway 4 is a close space defined by the walls of the internal chambers of the pneumatic cylinder and the main body. The connecting airway 4 has a perforation for communicating the connecting airway 4 with other internal space of the pneumatic tool 1 to form a complete airflow path.
With respect to the connecting airway 4 of the conventional technique, the mating plane face between the cylinder and the main body is parallel to the axis of the cylindrical body of the pneumatic cylinder. In addition, the cylinder is connected with the main body by several thread rods parallel to the axis of the cylindrical body. In other words, the direction of the connecting force between the cylinder and the main body is parallel to the connecting plane face. Accordingly, the connecting force cannot truly provide an airtight effect for the connecting airway 4 defined by the cylinder 2 and the main body 3. As a result, it cannot be ensured that the connecting airway keeps in an airtight state. Therefore, the air may escape. 